<?php

if (!defined('BASEPATH'))
  exit('No direct script access allowed');
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package		CodeIgniter
 * @author		ExpressionEngine Dev Team
 * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.
 * @license		http://codeigniter.com/user_guide/license.html
 * @link		http://codeigniter.com
 * @since		Version 1.0
 * @filesource
 */
// ------------------------------------------------------------------------

/**
 * CodeIgniter Hooks Class
 *
 * Provides a mechanism to extend the base system without hacking.
 *
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	Libraries
 * @author		ExpressionEngine Dev Team
 * @link		http://codeigniter.com/user_guide/libraries/encryption.html
 */
class CI_Hooks {

  /**
   * Determines wether hooks are enabled
   *
   * @var bool
   */
  var $enabled = FALSE;

  /**
   * List of all hooks set in config/hooks.php
   *
   * @var array
   */
  var $hooks = array();

  /**
   * Determines wether hook is in progress, used to prevent infinte loops
   *
   * @var bool
   */
  var $in_progress = FALSE;

  /**
   * Constructor
   *
   */
  function __construct() {
    $this->_initialize();
    log_message('debug', "Hooks Class Initialized");
  }

  // --------------------------------------------------------------------

  /**
   * Initialize the Hooks Preferences
   *
   * @access	private
   * @return	void
   */
  function _initialize() {
    $CFG = & load_class('Config', 'core');

    // If hooks are not enabled in the config file
    // there is nothing else to do

    if ($CFG->item('enable_hooks') == FALSE) {
      return;
    }

    // Grab the "hooks" definition file.
    // If there are no hooks, we're done.

    if (defined('ENVIRONMENT') AND is_file(APPPATH . 'config/' . ENVIRONMENT . '/hooks.php')) {
      include(APPPATH . 'config/' . ENVIRONMENT . '/hooks.php');
    } elseif (is_file(APPPATH . 'config/hooks.php')) {
      include(APPPATH . 'config/hooks.php');
    }


    if (!isset($hook) OR ! is_array($hook)) {
      return;
    }

    $this->hooks = & $hook;
    $this->enabled = TRUE;
  }

  // --------------------------------------------------------------------

  /**
   * Call Hook
   *
   * Calls a particular hook
   *
   * @access	private
   * @param	string	the hook name
   * @return	mixed
   */
  function _call_hook($which = '') {
    if (!$this->enabled OR ! isset($this->hooks[$which])) {
      return FALSE;
    }

    if (isset($this->hooks[$which][0]) AND is_array($this->hooks[$which][0])) {
      foreach ($this->hooks[$which] as $val) {
        $this->_run_hook($val);
      }
    } else {
      $this->_run_hook($this->hooks[$which]);
    }

    return TRUE;
  }

  // --------------------------------------------------------------------

  /**
   * Run Hook
   *
   * Runs a particular hook
   *
   * @access	private
   * @param	array	the hook details
   * @return	bool
   */
  function _run_hook($data) {
    if (!is_array($data)) {
      return FALSE;
    }

    // -----------------------------------
    // Safety - Prevents run-away loops
    // -----------------------------------
    // If the script being called happens to have the same
    // hook call within it a loop can happen

    if ($this->in_progress == TRUE) {
      return;
    }

    // -----------------------------------
    // Set file path
    // -----------------------------------

    if (!isset($data['filepath']) OR ! isset($data['filename'])) {
      return FALSE;
    }

    $filepath = APPPATH . $data['filepath'] . '/' . $data['filename'];

    if (!file_exists($filepath)) {
      return FALSE;
    }

    // -----------------------------------
    // Set class/function name
    // -----------------------------------

    $class = FALSE;
    $function = FALSE;
    $params = '';

    if (isset($data['class']) AND $data['class'] != '') {
      $class = $data['class'];
    }

    if (isset($data['function'])) {
      $function = $data['function'];
    }

    if (isset($data['params'])) {
      $params = $data['params'];
    }

    if ($class === FALSE AND $function === FALSE) {
      return FALSE;
    }

    // -----------------------------------
    // Set the in_progress flag
    // -----------------------------------

    $this->in_progress = TRUE;

    // -----------------------------------
    // Call the requested class and/or function
    // -----------------------------------

    if ($class !== FALSE) {
      if (!class_exists($class)) {
        require($filepath);
      }

      $HOOK = new $class;
      $HOOK->$function($params);
    } else {
      if (!function_exists($function)) {
        require($filepath);
      }

      $function($params);
    }

    $this->in_progress = FALSE;
    return TRUE;
  }

}

// END CI_Hooks class

/* End of file Hooks.php */
/* Location: ./system/core/Hooks.php */